Comparison Research On Passive Sampler And Active Sampler For Benzene, Toluene And Xylenes Personal Sampling

Being a carcinogenic to humans and widely used in industry, Benzene is a very harmful compound in occupational health. Between 1989～2003, Benzene poisoning number took the third in chemical poisoning. In workplace occupational hazards testing and evaluation, it's usual to sample Benzene and its homologues, and the workload is huge. Since 2002, GBZ 2-2002 Occupational Exposure Limit for Hazardous Agents in the Workplace has come into effect, PC-TWA (permissible concentration-time weighted average) has became Benzene and its homologues' Occupational Exposure Limit. Therefore Personal sampling technology for Benzene and its homologues has developed fast. Nowadays, the main personal sampling method is active sampling. Although the active sampler has lots of advantages, it also has many disadvantages such as dis-portable, hard to monitoring, unstable and so on. The passive sampler can make up those disadvantages, so it can act as a complement for active sampler in some country..Objectives to discuss the possibility of using passive sampler in Benzene, Toluene and Xylenes personal sampling, to compare the measure results between the passive samplers (GJ-1,3M 3500 we named them as type-Ⅰand type-Ⅱ,but not point out witch one is type-Ⅰ) and an active sampler (TWA-300H) for Benzene, Toluene and Xylenes personal sampling.Methods The lab-based comparisons were conducted in an environmental chamber where the two kinds of sampling devices were simultaneously exposed to nominally known concentrations of Benzene, Toluene and Xylenes.Field samples were obtained at 2 workplaces, workers were asked to wear a passive sampler and a charcoal tube sampling train for 4h.and the data were analysised with SAS 8.0 t-test or Wilcoxon rank sum test. Precision were evaluated for each passive sampler and were compared to the standard. Results In the lab-based comparisons most test results of 2 type of passive sampler showed a good consistency with the test results of the active sampler (p> 0.05). But there were a significant different between typeⅠpassive sampler and the active sampler for only one compound:benzene (P=0.0088 or P=0.0281). The field sample showed the same results.The analysis of 3 type of sampler's precision showed that the active sampler's RSD is 6.7%～11.1%, typeⅠpassive sampler with 11.8%～13.0%, and typeⅡpassive sampler had a large RSD range, with the maxium 32.3%.Conclusions There is a significant different between typeⅠpassive sampler and the active sampler for only one compound:benzene. There is no significant different between the typeⅠ/typeⅡpassive sampler and the active sampler for Toluene and Xylenes. The active sampler is recommended to be used as a complement for the active sampler.